staging: bcm2835-audio: Check if workqueue allocation failed

Currently, if allocating a workqueue fails, the driver will probe
successfully but it will silently do nothing, which is rather silly.
So instead bail out with -ENOMEM in bcm2835_audio_open() if
alloc_workqueue() fails, and remove the now pointless checks for a NULL
workqueue.

While at it, get rid of the rather pointless one-line function
my_workqueue_init().
Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c

@@ -117,7 +117,6 @@ static void my_wq_function(struct work_struct *work)
 
 int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
 {
-	if (alsa_stream->my_wq) {
 	struct bcm2835_audio_work *work;
 
 	work = kmalloc(sizeof(*work), GFP_ATOMIC);
@@ -133,13 +132,11 @@ int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
 		kfree(work);
 		return -EBUSY;
 	}
-	}
 	return 0;
 }
 
 int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
 {
-	if (alsa_stream->my_wq) {
 	struct bcm2835_audio_work *work;
 
 	work = kmalloc(sizeof(*work), GFP_ATOMIC);
@@ -155,14 +152,12 @@ int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
 		kfree(work);
 		return -EBUSY;
 	}
-	}
 	return 0;
 }
 
 int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
 			unsigned int count, void *src)
 {
-	if (alsa_stream->my_wq) {
 	struct bcm2835_audio_work *work;
 
 	work = kmalloc(sizeof(*work), GFP_ATOMIC);
@@ -180,22 +175,14 @@ int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
 		kfree(work);
 		return -EBUSY;
 	}
-	}
 	return 0;
 }
 
-static void my_workqueue_init(struct bcm2835_alsa_stream *alsa_stream)
-{
-	alsa_stream->my_wq = alloc_workqueue("my_queue", WQ_HIGHPRI, 1);
-}
-
 static void my_workqueue_quit(struct bcm2835_alsa_stream *alsa_stream)
 {
-	if (alsa_stream->my_wq) {
 	flush_workqueue(alsa_stream->my_wq);
 	destroy_workqueue(alsa_stream->my_wq);
 	alsa_stream->my_wq = NULL;
-	}
 }
 
 static void audio_vchi_callback(void *param,
@@ -436,7 +423,9 @@ int bcm2835_audio_open(struct bcm2835_alsa_stream *alsa_stream)
 	int status;
 	int ret;
 
-	my_workqueue_init(alsa_stream);
+	alsa_stream->my_wq = alloc_workqueue("my_queue", WQ_HIGHPRI, 1);
+	if (!alsa_stream->my_wq)
+		return -ENOMEM;
 
 	ret = bcm2835_audio_open_connection(alsa_stream);
 	if (ret) {